Masterfamily C3/20

Cost effective and small M-Bus Display / Datalogger for up to 3 or 20 meters.


  • Levelconverter for up to 3 or 20 meters
  • Mounting on DIN rail
  • Operation of all meters according to EN1434-3
  • Independent M-bus Display
  • Data filtering
  • Updatable
  • Data transmission rates 300.. 9600 Baud
  • Echo suppression
  • Durable short circuit proof
  • Operated locally by keyboard and LCD


  • Like M-Bus Display, but additionally with adjustable periodic bus read out and storage of meter data
  • Presentation of historical meter data on LCD
  • 1MByte Flash memory, optionally up to 4MByte

C3 / C20 - the ideal master for your small M-Bus installation.
The members of the C3/C20 family are ideally suited for M-Bus installations with up to 3 or 20 meters.
All devices offer a RS232C to M-Bus level converter function for remote read-out of meter-data by a PC with software.

Additionally the M-Bus Display allows real stand-allone operation with the integrated LCD and keypad.
Therefore meter data can be displayed on-site with few keystrokes.

The M-Bus Data Logger version is also able to save meter data automatically at free selectable times.
For this purpose even the standard version of the M-Bus Data Logger is equipped with large memory, 
which can also be extended if it is required. The collected data can be read out and evaluated by PC, Laptop or Modem at any time. 
The scope of supply contains the software FService, which makes set-up and parametrization of the masters much easier.


Technical Data

Operating voltage

11V .. 28VDC / 13V .. 28VAC
Power Input5WDC/9WAC
Temperature range0..55oC
M-Bus voltage32V (Mark, without load)
M-Bus current (C20)max. 30mA (20 unit loads)
M-Bus current (C3)max. 4,5mA (3 unit loads)

Overcurrent threshold


Internalbus resistance

approx. 100 Ω

Transmission speed

300 .. 9600 Baud

Galvanical isolation



 light-grey plastic, protection type
IP40 H x W x D: 58 x 106 x 96 mm
for DIN rail EN50022 TS35

LED indicatorPower

Control panel:

4 pushbutton switches
LCD with 2 lines a. 16 columns,


M-Bus, RS232
Screw Terminals

M-Bus (3-times),
power supply (GND, TXD, RXD)

Plug-in terminals

2 RS232 as 9-pin. DSUB-socket
1 x PC / 1 x Modem

Data memory
(just at MR00xDL)

(shared to the number of meters)
1MB standard, 2MB or 4MB on


Ordering information

Order NumberDescription
MR005FAM-Bus Display for 3 meters
MR005DLM-Bus Datalogger for 3 meters
MR006FAM-Bus Display for 20 meters
MR006DLM-Bus Datalogger für 20 meters

Firmware C20 family, ZIP with all variants